Statoliths
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. Idade, maturação e crescimento sazonal do calamar-argentino de nadadeira curta Illex argentinus (Cephalopoda: Ommastrephidae) pescada comercialmente no sul do Brasil / Ageing, maturation and seasonal growth of the Argentine short-finned squid Illex argentinus (Cephalopoda: Ommastrephidae) commercially fished in southern Brazil
Exemplares de Illex argentinus capturados pela pesca comercial ao longo do sul do Brasil foram amostrados mensalmente de Março de 2007 a Janeiro de 2008, para comprimento dorsal do manto (ML), sexo, idade e maturidade e para comparação entre estação fria (Junho-Novembro) e estação quente (Dezembro-Maio). Os machos foram 51.5% da amostra, 106-330 mm, 9
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/03/2011
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2. How to Activate a Plant Gravireceptor. Early Mechanisms of Gravity Sensing Studied in Characean Rhizoids during Parabolic Flights1
Early processes underlying plant gravity sensing were investigated in rhizoids of Chara globularis under microgravity conditions provided by parabolic flights of the A300-Zero-G aircraft and of sounding rockets. By applying centrifugal forces during the microgravity phases of sounding rocket flights, lateral accelerations of 0.14g, but not of 0.05g, resulted
American Society of Plant Biologists.
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3. The response to gravity is correlated with the number of statoliths in Chara rhizoids.
In contrast to higher plants, Chara rhizoids have single membrane-bound compartments that appear to function as statoliths. Rhizoids were generated by germinating zygotes of Chara in either soil water (SW) medium or artificial pond water (APW) medium. Differential-interference-contrast microscopy demonstrated that rhizoids form SW-grown plants typically co
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4. Do Starch Statoliths Act as the Gravisensors in Cereal Grass Pulvini? 1
To determine if starch statoliths do, in fact, act as gravisensors in cereal grass shoots, starch was removed from the starch statoliths by placing 45-day-old intact barley plants (Hordeum vulgare cv `Larker') in the dark at 25°C for 5 days. Evidence from staining with I2-KI, scanning electron microscopy, and transmission electron microscopy indicated that
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5. Amyloplast Sedimentation Dynamics in Maize Columella Cells Support a New Model for the Gravity-Sensing Apparatus of Roots1
Quantitative analysis of statolith sedimentation behavior was accomplished using videomicroscopy of living columella cells of corn (Zea mays) roots, which displayed no systematic cytoplasmic streaming. Following 90° rotation of the root, the statoliths moved downward along the distal wall and then spread out along the bottom with an average velocity of
American Society of Plant Physiologists.
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6. Tip-Growing Cells of the Moss Ceratodon purpureus Are Gravitropic in High-Density Media1
Gravity sensing in plants and algae is hypothesized to rely upon either the mass of the entire cell or that of sedimenting organelles (statoliths). Protonemata of the moss Ceratodon purpureus show upward gravitropism and contain amyloplasts that sediment. If moss sensing were whole-cell based, then media denser than the cell should prevent gravitropism or re
American Society of Plant Biologists.
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7. The Influence of Gravity on the Formation of Amyloplasts in Columella Cells of Zea mays L
Columella (i.e., putative graviperceptive) cells of Zea mays seedlings grown in the microgravity of outer space allocate significantly less volume to putative statoliths (amyloplasts) than do columella cells of Earth-grown seedlings. Amyloplasts of flight-grown seedlings are significantly smaller than those of ground controls, as is the average volume of ind
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8. Involvement of the Vacuoles of the Endodermis in the Early Process of Shoot Gravitropism in Arabidopsis
The endodermal cells of the shoot are thought to be the gravity-sensing cells in Arabidopsis. The amyloplasts in the endodermis that sediment in the direction of gravity may act as statoliths. Endodermis-specific expression of SGR2 and ZIG using the SCR promoter could complement the abnormal shoot gravitropism of the sgr2 and zig mutants, respectively. The a
American Society of Plant Biologists.
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9. Curvature Induced by Amyloplast Magnetophoresis in Protonemata of the Moss Ceratodon purpureus1
After gravistimulation of Ceratodon purpureus (Hedw.) Brid. protonemata in the dark, amyloplast sedimentation was followed by upward curvature in the wild-type (WT) and downward curvature in the wwr mutant (wrong way response). We used ponderomotive forces induced by high-gradient magnetic fields (HGMF) to simulate the effect of gravity and displace th
American Society of Plant Physiologists.
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10. Interaction between Gravitropism and Phototropism in Sporangiophores of Phycomyces blakesleeanus1
The interaction between gravitropism and phototropism was analyzed for sporangiophores of Phycomyces blakesleeanus. Fluence rate-response curves for phototropism were generated under three different conditions: (a) for stationary sporangiophores, which reached photogravitropic equilibrium; (b) for sporangiophores, which were clinostated head-over during phot
American Society of Plant Physiologists.
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11. Mutations in the Gravity Persistence Signal Loci in Arabidopsis Disrupt the Perception and/or Signal Transduction of Gravitropic Stimuli1
Gravity plays a fundamental role in plant growth and development, yet little is understood about the early events of gravitropism. To identify genes affected in the signal perception and/or transduction phase of the gravity response, a mutant screen was devised using cold treatment to delay the gravity response of inflorescence stems of Arabidopsis. Inflores
American Society of Plant Biologists.